The crash took place about 7.20am on Monday at Rolleston Drive and involved a truck and a light truck.
The driver of the light truck died at the scene, a police spokesperson said.
SH1 and Rolleston Drive remain closed this morning.
Police said diversions are in place along Tennyson St towards Dunns Crossing via Lowes Rd.
SH1 is likely to be closed for "several hours while the serious crash unit investigates", the spokesperson said.
A Waka Kotahi NZTA spokesperson said motorists should expect delays. The following detours are in place.
• Northbound traffic turn left onto Walkers Rd, right onto Two Chains Rd continuing onto Jones Rd, right onto Hoskyns Rd back onto SH1.
• Southbound traffic turn left onto Tennyson St then right onto Byron St continuing onto Brookside Rd and right onto Dunning Crossing Rd back onto SH1.
"Road users should take extra care and expect delays until this has been cleared," said the NZTA spokesperson.
"Due to the nature of the crash, this closure (SH1) is likely to remain in place for an extended period of time."
